mbsrtowcs - convert a multibyte string to a wide-character string
#include <wchar.h>
size_t mbsrtowcs(wchar_t *dest, const char **src,
size_t len, mbstate_t *ps);
If dest
is not NULL, the mbsrtowcs() function converts the multibyte string *src
to a wide-character string starting at dest
. At most len
wide characters are written to dest
. The shift state *ps
is updated. The conversion is effectively performed by repeatedly calling mbrtowc(dest, *src, n, ps)
where n
is some positive number, as long as this call succeeds, and then incrementing dest
by one and *src
by the number of bytes consumed. The conversion can stop for three reasons:
An invalid multibyte sequence has been encountered. In this case, *src
is left pointing to the invalid multibyte sequence, (size_t) -1
is returned, and errno
is set to EILSEQ.
len
non-L'\0' wide characters have been stored at dest
. In this case, *src
is left pointing to the next multibyte sequence to be converted, and the number of wide characters written to dest
is returned.
The multibyte string has been completely converted, including the terminating null wide character ('\0'), which has the side effect of bringing back *ps
to the initial state. In this case, *src
is set to NULL, and the number of wide characters written to dest
, excluding the terminating null wide character, is returned.
If dest
is NULL, len
is ignored, and the conversion proceeds as above, except that the converted wide characters are not written out to memory, and that no length limit exists.
In both of the above cases, if ps
is NULL, a static anonymous state known only to the mbsrtowcs() function is used instead.
The programmer must ensure that there is room for at least len
wide characters at dest
.
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
mbsrtowcs() | Thread safety | MT-Unsafe race:mbsrtowcs/!ps |
POSIX.1-2001, POSIX.1-2008, C99.
The behavior of mbsrtowcs() depends on the LC_CTYPE category of the current locale.
Passing NULL as ps
is not multithread safe.
iconv(3), mbrtowc(3), mbsinit(3), mbsnrtowcs(3), mbstowcs(3)
This page is part of release 4.15 of the Linux man-pages
project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.